1. Field of the Invention
This invention relates to a balustrade for use with passenger conveyors such as escalators, electrically operated passageways and the like and, more particularly, to a balustrade which is formed of stainless steel sheets.
2. Description of the Prior Art
Passenger conveyors have spread widely as fixtures which are indispensable to a building as a means for satisfying the needs of persons who utilize the building. In recent years, a variety of demands have been put forward for industrial designs of balustrades. As is well known, the balustrade constitutes a major part of a designed body in the passenger conveyor, and it is generally recognized by the parties concerned that whether the balustrade has an attractive industrial design or not is a major selling point in respect of making a discrimination among room designs.
As described in U.S. Pat. Nos. 3,321,059 and 3,353,650, the balustrade includes stationary members except for an endless series of steps adapted to convey passengers thereon, and moving parts such as handrails. As described above, each balustrade includes, as main components thereof, a main deck member upon which handrail is mounted, a lower deck member and a glass panel, all of which constitute an object for industrial design. It is conventional to form the main and lower deck members by extruded material of aluminum alloy, of which surfaces have been subjected to alumite treatment.
Aluminum alloy material has been widely used for the main and lower deck members of a balustrade since it is advantageous in its formability into substantially complex shapes. However, the use of this material has a disadvantage in that the manufacturing cost thereof continues to be increased due to high electric power consumption and the raw material therefor tends to be reduced. However, what is more significant than the high manufacturing cost is the fact that aluminum alloy material is relatively soft (as compared to such metallic materials as steel) to be readily marred. This presents a serious problem in which the respective members of balustrade present scratches and impressions on the inner sides thereof facing the steps after the members have been contacted by a large number of passengers during several years of operation. Thus such passenger conveyors present an unsightly appearance. Particularly in the case of passenger conveyors installed in underground markets, corrosion of the material of the balustrades caused by underground water adds to deterioration of the industrial design of the balustrades.
Therefore, stainless steel sheets have begun to be used in place of aluminum alloy material, which sheets are superior to the latter in price stabilization, hardness and anticorrosive resistance. However, the use of stainless steel for balustrades raises the technical problem of the material being deformed when worked to bend the same. Since this problem has not been solved satisfactorily, the practice of using a stainless steel sheet has not yet become popular.